Reputation: 43
Say I have a table like this:
df1 <- data.frame(x=1,y=1,z=1)
And I turn it into a tableGrob like this:
tableGrob(df1,rows = NULL) %>% grid.draw()
How do I add a line to the bottom?
I can add a line to the top like this:
tableGrob(df1,rows = NULL) %>% gtable_add_grob(
grobs = segmentsGrob( # line across the bottom
x0 = unit(0,"npc"),
y0 = unit(1,"npc"),
x1 = unit(2,"npc"),
y1 = unit(1,"npc"),
gp = gpar(lwd = 2)),
t = 1, b = 1, l = 1, r = 3) %>% grid.draw()
Or to the second line like this (changed t=1 to t=2 and b=1 to b=2):
tableGrob(df1,rows = NULL) %>% gtable_add_grob(
grobs = segmentsGrob( # line across the bottom
x0 = unit(0,"npc"),
y0 = unit(1,"npc"),
x1 = unit(2,"npc"),
y1 = unit(1,"npc"),
gp = gpar(lwd = 2)),
t = 2, b = 2, l = 1, r = 3) %>% grid.draw()
But when I try this (t=3 and b=3):
tableGrob(df1,rows = NULL) %>% gtable_add_grob(
grobs = segmentsGrob( # line across the bottom
x0 = unit(0,"npc"),
y0 = unit(1,"npc"),
x1 = unit(2,"npc"),
y1 = unit(1,"npc"),
gp = gpar(lwd = 2)),
t = 3, b = 3, l = 1, r = 3) %>% grid.draw()
I get the following error:
Error in grid.Call.graphics(C_setviewport, vp, TRUE) : invalid 'layout.pos.row'
Also, this does not work (t=2 and b=2, but y0=2 and y1=2):
tableGrob(df1,rows = NULL) %>% gtable_add_grob(
grobs = segmentsGrob( # line across the bottom
x0 = unit(0,"npc"),
y0 = unit(2,"npc"),
x1 = unit(2,"npc"),
y1 = unit(2,"npc"),
gp = gpar(lwd = 2)),
t = 2, b = 2, l = 1, r = 3) %>% grid.draw()
Any ideas? Why specifically did the attempts to add a line at the bottom fail?
Upvotes: 1
Views: 1761
Reputation: 849
Table
df1 <- data.frame(x=1,y=1,z=1)
Assign to the Variable g1
g1 <- tableGrob(df1,rows = NULL)
g1 <- gtable_add_grob(g1,
grobs = segmentsGrob( # line across the bottom
x0 = unit(0,"npc"),
y0 = unit(0,"npc"),
x1 = unit(1,"npc"),
y1 = unit(0,"npc"),
gp = gpar(lwd = 2.0)),
t = 2, b = 2, l = 1, r = ncol(g1))
grid.draw(g1)
Upvotes: 1